Sennheiser MAS 133 Review

Overview

The Sennheiser MAS 133 is not a speaker or a standalone microphone, but a specialized professional audio tool. It functions as an intelligent inline switch box for any microphone that connects via a standard 3-pin XLR cable. Positioned between the microphone and a mixing desk or audio interface, its primary role is to provide simple, reliable control over when a mic is active. It also supplies power to accessory microphone buttons, like Sennheiser's own MAS 1, and offers several programmable modes to suit different use cases, from presentations to panel discussions.

Targeted at system integrators and AV professionals, the MAS 133 solves a common problem: giving a presenter intuitive control over their microphone without needing to interact with a complex mixing board. By including professional-grade features like multiple activation modes and a TTL logic output for controlling other equipment, Sennheiser has created a flexible component for integrated AV systems.

Please note: The Sennheiser MAS 133 is a professional audio accessory for controlling microphones. It is not a wireless speaker, a standalone microphone, or a consumer audio device. It requires an external XLR microphone, an audio mixer or interface, and a source of P48 phantom power to operate.

Key Features

The MAS 133 may be a compact device, but it packs in several useful features for professional audio setups. Its core value lies in its versatile microphone control modes and its ability to integrate with wider AV systems.

Switchable Microphone Activation Modes

The standout feature of the MAS 133 is its quartet of user-selectable microphone control modes. This allows an installer to configure the microphone's behavior to precisely match the application. The modes include Toggle On/Off (press once to talk, press again to mute), Push-to-Talk (PTT, the mic is only active while the button is held down), and Push-to-Mute (PTM, the inverse of PTT where the mic is always on unless the button is held). There is also a "Permanent On" mode, which effectively bypasses the switching function. This flexibility ensures the microphone behaves predictably for presenters, panelists, or anyone who needs to speak, reducing the chance of error during a live event or recording.

TTL Logic for System Integration

Beyond simple audio switching, the MAS 133 includes a TTL logic output. This is a powerful feature for automated AV setups. When the microphone is activated, the MAS 133 can send a voltage signal to a third-party control system. This signal can be used to trigger other actions automatically. For example, it could command a video switcher to select the camera pointed at the speaker, signal a lighting system to change the room's look, or start and stop a recording device. This turns a simple microphone switch into a control point for an entire integrated room system.

For advanced automation, the TTL logic output can be connected to a control system like Crestron or AMX to automatically switch cameras, adjust lighting, or start recordings whenever the microphone is activated. This can significantly streamline the operation of presentations or conferences.

Specifications

Design & Build

The MAS 133 is a purely functional device, designed for discreet installation. It's a compact, rectangular box measuring approximately 5.9 inches long. The chassis features a 3-pin XLR input on one end and a 3-pin XLR output on the other, allowing it to be inserted "inline" with a standard microphone cable run. Weighing just 212 grams, it's lightweight enough to be mounted conveniently out of sight—under a table, inside a podium, or on a rack. The unit ships with two mounting brackets and screws, reinforcing the idea that it is intended for permanent or semi-permanent installation rather than portable use.

Who It's For

The Sennheiser MAS 133 is built for a very specific professional audience. Its primary users will be AV system integrators and technicians who are designing and installing audio systems in spaces like corporate boardrooms, university lecture halls, government chambers, hotels, and houses of worship. It is an ideal component for any scenario where a presenter needs a simple, physical button to control their microphone without having to rely on a touchscreen or a remote technician.

It is not a consumer product and would have little to no use in a home studio or for casual recording, where microphone control is typically handled directly on an audio interface or in software. This is a problem-solver for permanently installed, multi-component AV systems where reliability and ease of use are paramount.

The MAS 133 is designed to work seamlessly with Sennheiser's MAS 1 microphone button, which provides the physical switch for the presenter. While the MAS 133 can be triggered by other means, it is intended to be part of this ecosystem for a complete solution.

Pros

• Four versatile microphone control modes (PTT, PTM, Toggle, On)
• TTL logic output enables integration with camera and media control systems
• Uses standard 3-pin XLR connectors for wide compatibility
• Powered by standard P48 phantom power, no batteries or separate PSU needed
• Compact, lightweight design with included mounting brackets

Cons

• Niche product for professional installations only
• Requires an external microphone button (like the Sennheiser MAS 1) for full functionality
• Wired connection may limit placement options

FAQ

Yes, the MAS 133 connects via standard 3-pin XLR cables, so it can be placed in line with any wired XLR microphone. However, to use its switching functionality, you need a compatible microphone button like the Sennheiser MAS 1 connected to it.

No, the MAS 133 does not use or include a battery. It is powered by the P48 phantom power supplied by the mixing console or audio interface it is connected to.

The TTL logic output is an advanced feature that allows the MAS 133 to control other devices. When the microphone is turned on, the MAS 133 sends a signal that can be used to automatically trigger actions like switching a video camera to the current speaker or activating a recording light.

While technically possible, the MAS 133 is not designed for home studio use. It is a professional installation component for conference rooms and lecture halls. Most home users will find that the controls on their audio interface or in their recording software are more than sufficient.

Related Reads

• Sennheiser brand page

Pros

• Offers four distinct microphone control modes: Push-to-Talk, Push-to-Mute, Toggle, and Permanent On.
• Features a TTL logic output (> 2.4 V) for seamless integration with AV control systems, cameras, and recording devices.
• Utilizes standard 3-pin XLR connectors for broad compatibility with most professional microphones.
• Operates on P48 phantom power, eliminating the need for batteries or an external power supply.
• Has a compact and lightweight design (212 g) with included mounting brackets for discreet installation.
• The unit is designed to be inserted inline with a standard microphone cable.
• Supports operation within a wide temperature range of 14° to 122°F.

Cons

• Requires an external microphone and an audio mixer or interface to function.
• The MAS 133 is a specialized professional tool, not suitable for consumer or home studio use.
• Its function is primarily for wired installations, potentially limiting placement flexibility for the microphone itself.
• Intended to work seamlessly with the Sennheiser MAS 1 microphone button, suggesting it's part of a specific ecosystem.
• Does not include a physical button; it requires a separate accessory to trigger its functions for the presenter.

Verdict

Based on the specifications, the Sennheiser MAS 133 is a well-defined and highly practical tool for the professional AV market. Its utility will ultimately depend on the specific demands of the installation, but its feature set is directly aligned with the needs of modern conference and presentation spaces.